There are plenty of people on here with VASTLY more knowledge than myself, but to simplify things.

Nymphs- For the most part (for me) it is a dead drift in faster water. I use an indicator most of the time but if I'm fishing shallower water (less than 3 ft) I will go with a hopper dropper setup

Streamers- Again for the most part- I fish them almost like I'm fishing convential for bass, 45 degree casts upstream and depending how slow or fast the fish tell me i strip it back. and yes this is for trout